This project will conduct a detailed techno-economic feasibility analysis to identify cost-effective, resilient, and robust technology options that support the simultaneous heating and cooling needs of co-located buildings. Designed for applicability across a range of Department of Defense (DoD) sites, this effort will analyze a thermal reservoir network—an advanced thermal microgrid that utilizes a near-ambient temperature water distribution loop. By integrating local thermal sources, sinks, and storage with energy transfer stations equipped with reversible heat pumps, this system will provide a more efficient, flexible, and scalable alternative to traditional HVAC infrastructure.

The design enhances energy resilience by enabling load shifting and controlled dispatch of technology, ensuring uninterrupted operations even under extreme conditions. Through simulations, this project will demonstrate annual system-level performance with a targeted seasonal performance factor of 6–8, a 20–30% peak load reduction, and a 50% reduction in power demand during resilience events. Life cycle costs are projected to remain under $0.20/kWh, making this a cost-effective solution that aligns with DoD priorities for energy security and fiscal responsibility. The modular design of the thermal reservoir network allows DoD to phase in the system as capital becomes available, reducing upfront financial burdens while maintaining flexibility for site-specific energy needs.

This project will conduct a techno-economic feasibility analysis of optimized system configurations to demonstrate the broad applicability of this energy concept across DoD installations. The project will deliver a conceptual energy and control system design with quantified benefits in energy efficiency, power management, resilience, and cost reduction, while also providing guidance for extending the design to other military sites.

The innovation in this approach is threefold. First, thermal reservoir networks achieve exceptionally high efficiency by leveraging geothermal coupling with the ground and local water bodies as heat sources and sinks, utilizing waste heat from one building to supply another, and integrating modular energy generation and storage technologies. The system’s advanced control capabilities enable dynamic load shifting across energy carriers, reducing peak demand and improving energy reliability during resilience events.

Second, the thermal reservoir network is designed for modular expansion, allowing phased investment and customized adaptation to different DoD sites. This ensures that installations can build out these systems incrementally without requiring large, upfront capital expenditures.

Third, this project will use cutting-edge Modelica-based simulation technologies to model and analyze the system’s performance. Unlike conventional load-based simulations, which lack the capability to accurately express controls and piping networks, the Modelica approach allows for the rapid development and testing of advanced control sequences. These digital twin models will support system implementation, commissioning, and operation using open standards, significantly reducing the risk of deploying a system that currently has limited design and installation experience in the U.S.

Compared to state-of-the-art district energy systems, thermal reservoir networks offer multiple advantages. The use of a single, non-insulated distribution pipe reduces trenching and infrastructure costs while maintaining efficient energy transfer. Capital expenses are further minimized through a modular design that allows phased implementation and reduces the required capacity of central equipment. Energy costs and overall demand are significantly reduced by capturing and repurposing low-grade waste heat, utilizing existing thermal sources and sinks, and optimizing system efficiency through advanced controls.

By eliminating the need for large central plants and leveraging distributed energy resources, this approach supports DoD’s commitment to energy resilience, cost-effective modernization, and mission readiness. This project directly aligns with national priorities to strengthen domestic energy independence, reduce government spending, and enhance military operational effectiveness through smarter, more efficient infrastructure investments.